Curcumin combined with red united blue light did not induce toxic membrane damage.

HaCaT cells were pre-incubated with curcumin (0–5 μM) for 2 h, and then separately irradiated with blue light, red light and two combinations of blue and red light, or protected from light. The lactate dehydrogenase (LDH) concentration in the cell-free supernatants was measured 20 h later. Cells treated with 1% Triton X-100 served as a positive control. All values were referred to the positive control. The assessment was implemented by three independent experiments.